glibc/nptl/pthread_rwlock_wrlock.c
Ulrich Drepper eb7721f232 * pthread_rwlock_rdlock.c (__pthread_rwlock_rdlock): Add LLL_SHARED
parameter to lll_futex_wait call.
	* pthread_rwlock_wrlock.c (__pthread_rwlock_wrlock): Likewise.

	* sysdeps/unix/sysv/linux/powerpc/pthread_once.c (__pthread_once):
	Replace lll_futex_wait with lll_private_futex_wait.
	* sysdeps/unix/sysv/linux/powerpc/sem_post.c (__new_sem_post):
	Add LLL_SHARED parameter to lll_futex_wake().

	* sysdeps/unix/sysv/linux/powerpc/lowlevellock.h: Define LLL_PRIVATE
	LLL_SHARED, lll_private_futex_wait, lll_private_futex_timed_wait and
	lll_private_futex_wake.
	(lll_futex_wait): Add private parameter. Adjust FUTEX_PRIVATE_FLAG
	bit from private parm before syscall.
	(lll_futex_timed_wait): Likewise.
	(lll_futex_wake): Likewise.
	(lll_futex_wake_unlock): Likewise.
	(lll_mutex_unlock): Add LLL_SHARED parm to lll_futex_wake call.
	(lll_robust_mutex_unlock): Likewise.
	(lll_mutex_unlock_force): Likewise.
	(lll_wait_tid): Add LLL_SHARED parm to lll_futex_wait call.
2007-07-23 16:07:53 +00:00

90 lines
2.7 KiB
C

/* Copyright (C) 2003, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <sysdep.h>
#include <lowlevellock.h>
#include <pthread.h>
#include <pthreadP.h>
/* Acquire write lock for RWLOCK. */
int
__pthread_rwlock_wrlock (rwlock)
pthread_rwlock_t *rwlock;
{
int result = 0;
/* Make sure we are along. */
lll_mutex_lock (rwlock->__data.__lock);
while (1)
{
/* Get the rwlock if there is no writer and no reader. */
if (rwlock->__data.__writer == 0 && rwlock->__data.__nr_readers == 0)
{
/* Mark self as writer. */
rwlock->__data.__writer = THREAD_GETMEM (THREAD_SELF, tid);
break;
}
/* Make sure we are not holding the rwlock as a writer. This is
a deadlock situation we recognize and report. */
if (__builtin_expect (rwlock->__data.__writer
== THREAD_GETMEM (THREAD_SELF, tid), 0))
{
result = EDEADLK;
break;
}
/* Remember that we are a writer. */
if (++rwlock->__data.__nr_writers_queued == 0)
{
/* Overflow on number of queued writers. */
--rwlock->__data.__nr_writers_queued;
result = EAGAIN;
break;
}
int waitval = rwlock->__data.__writer_wakeup;
/* Free the lock. */
lll_mutex_unlock (rwlock->__data.__lock);
/* Wait for the writer or reader(s) to finish. */
lll_futex_wait (&rwlock->__data.__writer_wakeup, waitval,
// XYZ check mutex flag
LLL_SHARED);
/* Get the lock. */
lll_mutex_lock (rwlock->__data.__lock);
/* To start over again, remove the thread from the writer list. */
--rwlock->__data.__nr_writers_queued;
}
/* We are done, free the lock. */
lll_mutex_unlock (rwlock->__data.__lock);
return result;
}
weak_alias (__pthread_rwlock_wrlock, pthread_rwlock_wrlock)
strong_alias (__pthread_rwlock_wrlock, __pthread_rwlock_wrlock_internal)